Externally mountable spiral adaptor

ABSTRACT

An adaptor that can be used with rotary fluid equipment will protect mechanical seals and/or packing material adjacent a seal cavity ( 18 ) of the equipment. The adaptor includes an annular body ( 30 ) with a central bore ( 32 ) adapted to receive a shaft ( 12 ) of the equipment. When used with mechanical seals the adaptor is receivable in the cavity at the entrance thereto and it has a portion which surface which effects contact with a complementary surface of the seal. When used with packing the adaptor fits within the cavity and defines an outboard extension in which the packing can be received. The bore defines two portions, one of which is close to the shaft ( 52 ) and another portion ( 54 ) which flares outwardly from the one portion towards the outboard end of the adaptor. Each bore portion has a spiral groove ( 56,58 ) therein, which groove serves to redirect contaminant material contained in fluids surrounding the shaft away from the seal cavity.

FIELD OF THE INVENTION

The present invention relates to an adaptor that can be used withrotatable fluid equipment, such as pumps, and which will protectmechanical seals and packing adjacent a seal cavity of the equipment.

BACKGROUND OF THE INVENTION

Spiral throat bushings are available from EnviroSeal EngineeringProducts Ltd. of Waverley, Nova Scotia, Canada under the SpiralTrac™name. These patented devices (U.S. Pat. No. 5,553,868) have a spiralgroove formed in a sloping face thereof and are generally positioned atthe “bottom” of a seal cavity defined in part by a rotating shaft, ashaft housing, and a throat structure. The seal cavity typically, aswell, may be filled with conventional packing or it may include amechanical seal adjacent the end opposite the throat structure. Thesespiral bushings are intended to remove particulate material that mayaccumulate within the seal cavity during operation of the equipment, andmay be augmented by flush fluids to help in material removal. The resultof using these “internal” spiral throat bushings has been increased sealor packing life due to a significant reduction in wear.

Mechanical seals are designed to prevent leakage of process fluid toatmosphere, and are typically offered in a split or solid cartridgedesign. Typically, the seal is fastened to the face of the seal cavityhousing by some mechanical means, such as threaded bolts or rods. Theoperation of the rotating equipment could be enhanced further if therewas less particulate material entering the seal cavity from the vicinityof the mechanical seal.

Packing material is typically provided in annular rings and one or moresuch packing rings can be placed in a seal cavity and surrounding therotating shaft. Again, operation of rotating equipment could be enhancedfurther if there were less particulate material entering the seal cavitypast or from the vicinity of such packing material

SUMMARY OF THE INVENTION

This need for reduction of particulate or contaminant material from theexterior of the seal cavity has led to the development of an “external”spiral adaptor or bushing that is positioned between the mechanical sealor packing and the end face of the seal cavity housing and which servesto increase the cleanliness of the environment in which the sealingmechanism, whether mechanical seal or packing, functions.

The advantage to this arrangement is that with the spiral adaptor beinglocated closer to the sealing mechanism the existing patented technologyof the bushing or adaptor will protect the sealing mechanism fromparticulate material entering at or near the sealing area. By doingthis, the intent is to allow the sealing mechanism to operate in acleaner environment with the result being extended operating life. Theexternally mounted design is available in a split and non-split (solid)design. The advantage of the split design is that the equipment does nothave to be disassembled and the benefit of the spiral adaptor technologycan be utilized. There are enormous savings for the customer if this canbe avoided. The advantage of the solid design resides in the spiraladaptor technology and the benefit of a cleaner operating environment.

The externally designed spiral adaptor of this invention will create anenclosed cavity for the rotating component of a mechanical seal.Furthermore, it is possible to dimension the outboard side of the deviceto accept virtually any mechanical seal or packing material that isavailable on the market. The mechanical seal or packing being utilizedwill determine the cavity depth of the externally mountable spiraladaptor of the invention.

In summary of the foregoing, and in one embodiment, the presentinvention may be broadly set forth as a spiral adaptor for location atan entrance to an annular seal cavity of rotating equipment, such sealcavity being defined by a outer cylindrical surface of a rotatable shaftof such equipment and a shaft housing surrounding at least a portion ofthe shaft, the cavity having a bottom end, an entrance end and an outercylindrical surface, the equipment including a mechanical sealpositioned outboard of the shaft housing adjacent the entrance to theseal cavity. The adaptor comprises: an annular adaptor body having acentral bore therethrough, the adaptor body including a first annularportion receivable within the seal cavity at the entrance thereto and asecond annular portion of greater diameter than the first annularportion, the second annular portion having an inboard radial surfaceadapted for contact with a complementary face of the shaft housing andan outboard radial surface adapted for contact with a complementary faceof the mechanical seal; the bore including a first portion defining anannular gap with the shaft outer cylindrical surface when the adaptor isin its operating position and a second portion which flares outwardlyfrom the first bore portion towards said outboard radial surface, thefirst and second bore portions each including a spiral groove formedtherein, the hand thereof being in the same direction as the rotation ofthe shaft, the groove serving to redirect contaminant material containedin fluids surrounding the shaft away from said the cavity.

In another related embodiment the present invention may be considered asproviding a spiral adaptor for location at an entrance to an annularseal cavity of rotating equipment, such seal cavity being defined by aouter cylindrical surface of a rotatable shaft of such equipment and ashaft housing surrounding at least a portion of the shaft, the cavityhaving a bottom end, an entrance end and an outer cylindrical surface,the equipment including a mechanical seal positioned outboard of theshaft housing adjacent the entrance to the seal cavity, the adaptorcomprising: an annular adaptor body receivable within the seal cavity atthe entrance thereto and having a central bore therethrough; the adaptorbody including an outboard radial surface adapted for contact with acomplementary face of the mechanical seal; the bore including a firstportion defining an annular gap with the shaft outer cylindrical surfacewhen the adaptor is in its operating position and a second portion whichflares outwardly from the first bore portion towards the outboard radialsurface, the first and second bore portions each including a spiralgroove formed therein, the hand thereof being in the same direction asthe rotation of the shaft, the groove serving to redirect contaminantmaterial contained in fluids surrounding the shaft away from the sealcavity.

In yet another related embodiment the present invention may beconsidered as providing a spiral adaptor for location within an annularseal cavity of rotating equipment, such seal cavity being defined by aouter cylindrical surface of a rotatable shaft of such equipment and ashaft housing surrounding at least a portion of the shaft, the cavityhaving a bottom end, an entrance end and an outer cylindrical surface,the adaptor comprising: an annular adaptor body receivable within theseal cavity and having a central bore therethrough; the adaptor bodyincluding a first annular body portion positionable at the bottom end ofthe seal cavity and a second annular body portion outboard the firstbody portion; the bore including a first portion defining an annular gapwith the shaft outer cylindrical surface when the adaptor is in itsoperating position and a second portion which flares outwardly from thefirst bore portion towards a radially inwardly tapering central portion,the first, second and central bore portions each including a spiralgroove formed therein, the hand thereof being in the same direction asthe rotation of the shaft, the groove serving to redirect contaminantmaterial contained in fluids surrounding the shaft away from said thecavity; and the adaptor also including an annular extension portionextending from the second annular portion to an outboard end of theadaptor, the extension portion including a blind bore therein which,with the shaft outer cylindrical surface, defines an annular cavity forreception of one or more packing rings.

The present invention will now be described with reference to thedrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates in partial cross-section a typical environment for aspiral adaptor of the present invention, as located at the entrance tothe seal cavity of rotating fluid equipment.

FIG. 2 illustrates in enlarged cross-section a first embodiment of thespiral adaptor of the present invention.

FIG. 3 illustrates in enlarged cross-section a second embodiment of thespiral adaptor of the present invention.

FIG. 4 illustrates in enlarged cross-section a third embodiment of thespiral adaptor of the present invention.

FIG. 5 illustrates in enlarged cross-section a fourth embodiment of thespiral adaptor of the present invention.

FIG. 6 illustrates in enlarged cross-section a fifth embodiment of thespiral adaptor of the present invention.

FIG. 7 illustrates in enlarged cross-section a sixth embodiment of thespiral adaptor of the present invention.

FIG. 8 illustrates in enlarged cross-section a seventh embodiment of thespiral adaptor of the present invention.

FIG. 9 illustrates in enlarged cross-section an eighth embodiment of thespiral adaptor of the present invention.

FIG. 10 illustrates in enlarged cross-section a ninth embodiment of thespiral adaptor of the present invention.

FIG. 11 illustrates in enlarged cross-section a tenth embodiment of thespiral adaptor of the present invention.

FIG. 12 illustrates in enlarged cross-section the spiral adaptor of thepresent invention as utilized in the arrangement of FIG. 11.

FIG. 13 illustrates in enlarged cross-section an eleventh embodiment ofthe spiral adaptor of the present invention.

FIG. 14 illustrates in enlarged cross-section the spiral adaptor of thepresent invention as utilized in the arrangement of FIG. 13.

DESCRIPTION OF THE PREFERRED AND OTHER EMBODIMENTS

FIG. 1 of the drawings illustrates a typical environment in which aspiral adaptor of the present invention will be useful. Such environmentis found in rotating fluid equipment, which equipment 10 will include arotatable shaft 12, bearingly mounted on an axis A, and surrounded atleast in part by a shaft housing 14. The housing 14 defines with anouter cylindrical surface 16 of the shaft 12 an annular seal cavity 18having a bottom end defined by radial flange 20, an entrance end 22 andan outer cylindrical surface 24. A mechanical seal 26 is typicallypositioned outboard of the seal cavity adjacent the shaft housing at theentrance to the seal cavity. The details of the mechanical seal are notgermane to the present invention and will not be described herein.

As seen in FIG. 1 there is an external spiral adaptor 28 of the presentinvention located at the entrance to the seal cavity, positioned so asto be between the housing 14 and the mechanical seal 26. The adaptor 28is described in greater detail with reference to FIG. 2.

Turning now to FIG. 2 a spiral adaptor 28 in accordance with the presentinvention will now be described. It is expected that this embodimentwill be the one most commonly used in existing and new rotary equipmentand it is the one depicted in position in FIG. 1. As with all of theembodiments to the described herein the spiral adaptor 28 can bemachined from a single billet of suitable material, such as stainlesssteel, PTFE, or PEEK. A composite such as PTFE or PEEK is preferredsince the machining time therefor is much less than with a metal. As iscommon in the adaptor art the spiral adaptor of the present inventionmay be formed as a solid (unitary) ring or it may be split into two ormore sections or segments, typically along a vertical or a horizontalaxis. If a split adaptor is used then the sections or segments thereofwill have suitable mating pins and holes to align the sections orsegments together, as well as appropriate fastening means, such asmachine screws, to hold them together.

The adaptor 28 has an annular adaptor body 30 having a central bore 32extending therethrough. The adaptor body includes a first annularportion 34 which is adapted for a tight fit within the seal cavity 18 atthe entrance 22 thereto. The annular portion 34 may include acircumferential groove 36 therein for reception of an annular sealingmember 38 (FIG. 1) such as an O-ring which will have sealing engagementwith the outer cylindrical surface 24 of the seal cavity 18 when thespiral adaptor is in position. The adaptor body includes a secondannular portion 40 of diameter greater than that of the first annularportion 34. The second annular portion 40 has an inboard radial surface42 adapted for contact with a complementary face surface 44 of the shafthousing 14 and an outboard radial surface 46 adapted for contact with acomplementary face surface 48 of the mechanical seal 26. The inboardradial surface 42 may be provided with a ribbed gasket surface 50 forsealing engagement with the complementary surface 44 of the housing 14.

It will be seen that the adaptor body bore 32 includes two portions, afirst portion 52 which defines an annular gap G (FIG. 1) with the outercylindrical surface 16 of the shaft 12 and a second portion 54 whichflares outwardly from the outboard end of the first portion 52 towardsthe outboard radial surface 46 of the second annular body portion 40.Each of the bore portions 52, 54 is provided with its own spiral groove56, 58 respectively therein, the hand of the spiral grooves 56, 58 beingin the same direction of the rotation of the shaft 12. The grooves 56,58 serve to redirect any contaminant-containing fluids away from theseal cavity such that damaging particulate material or othercontaminants contained within operating fluids will not enter the sealcavity.

The grooves 56, 58 are similar to those described in aforementioned U.S.Pat. No. 5,553,868 in that they include both radial and non-radialportions. The non-radial portions 60 extend non-radially into the bodyof the adaptor from the respective bore portion and the radial portions62 extend radially from the inner end of the respective non-radialportion back towards the bore. The groove 56 of the first bore portion52 will lead smoothly into the groove 58 of the second or flared boreportion 54.

Although not shown specifically within the drawings there could be oneor more additional grooves formed within the adaptor body and locatedbetween the first and second grooves 56, 58 also as described in U.S.Pat. No. 5,553,868.

FIG. 3 illustrates a variation on the embodiment of FIG. 2 which isintended to accommodate a situation in which there are restrictions onavailable axial space in which the spiral adaptor can be received. Inthis situation the adaptor 64 of FIG. 3 could be utilized, it beingnoted that the first annular body portion 66 is considerably shorter inaxial length than the second annular body portion 68. In this embodimentthe first body portion 66 acts only as a locating boss to hold thespiral adaptor in position while the equipment is being assembled, suchthat the adaptor is self-centring with respect to the seal cavity. Withthis embodiment the first annular body portion 66 is not long enough toinclude a circumferential groove and sealing member as is found in theembodiment of FIG. 2.

There may be situations in which there is a need to extend the firstannular body portion of the spiral adaptor deeply into the seal cavity,perhaps all the way to the bottom 18 thereof. The spiral adaptor 70 ofFIG. 4 will accomplish this need in that the first annular portion 72thereof is considerably longer than the second annular portion 74. Thefirst annular portion 72 is preferably provided with at least twocircumferential grooves 76, each of which can receive a suitable sealingmember, such as an O-ring as described for the first embodiment, toeffect sealing engagement with the outer cylindrical surface 24 of theseal cavity 18.

There may be situations in which there has been substantial wear on theshaft 12 in the vicinity of the mechanical seal 26 and it becomesdesirable to reposition the seal 26 further away from the shaft housing14 than before. The spiral adaptor 80 of FIG. 5 can be used in thesesituations, it being noted that the second annular body portion 84thereof is considerably greater in axial length than the first annularportion 82 thereof. With this embodiment the mechanical seal 26 can bemoved outwardly on the shaft 12 to a smoother area of the shaft or seal,with the greater length of the second annular body portion bridging thedistance from the housing 14 to the mechanical seal 26. Anotheradvantage to this embodiment is that the mechanical seal is positionedcloser to the main bearing support of the equipment where there is lesschance of vibration affecting the performance of the seal.

It will be appreciated that there are many designs of seal cavities andthat not all such designs will conform generally to the typical designillustrated in FIG. 1. One such non-conforming design is the so-called“big bore” design where a larger more expensive mechanical seal isrequired. By using the spiral adaptor 90 of FIG. 6 it is possible toreduce the radial cross-section of the adaptor, allowing for a smaller,less expensive, mechanical seal to be used. In this case the adaptorbody 92 does not include a second annular body portion of diametergreater than that of the first annular body portion, i.e. the body has asingle outer diameter over its entire length. Otherwise the features ofthe adaptor are the same as those of the first embodiment. Thisarrangement can substantially reduce costs for the customer.

FIG. 7 illustrates a spiral adaptor 100 that is advantageous in thosesituations where the complementary face surface 44 of the shaft housing14 is eroded or damaged and the ribbed gasket surface 50 will notprovide sufficient sealing contact with the face surface 44. In thisembodiment an annular groove 102 is machined in the inboard radialsurface 42 of the second annular portion 40 and a soft, flexible gasket104 is positioned in the groove, which gasket will effect suitablesealing contact with the complementary face surface 44. Should the facesurface 44 be eroded to the point where neither the ribbed gasketsurface 50 nor the separate gasket member 104 is acceptable, thecustomer may have to machine the face surface 44 back to its originalcondition before the spiral adaptor is assembled thereto.

Depending on the nature of the mechanical seals with which the presentinvention will be used it may become necessary to use a spiral adaptorin which the bore opens to the seal closer to the inboard end thereofthan in the other embodiments previously described. Thus there could beone or more intermediate bore portions between the first and second boreportions. Such spiral adaptor 110 is illustrated in FIG. 8, where asingle intermediate portion 112 is located between the first portion 114and the second, flared portion 116. The intermediate portion 112 isprovided with a spiral groove 118 which leads smoothly into the spiralgroove 120 of the flared bore portion 116. The transition 122 betweenthe first bore portion 114 and the intermediate portion 112 is alsoflared and includes a spiral groove 124, smoothly extending the groove126 of the first portion 114 to the spiral groove 118 of theintermediate portion. Such an embodiment can be used with mechanicalseal arrangements that are axially long, including both single anddouble mechanical seals. The length of the intermediate portion will beselected to accommodate the physical parameters of the equipment. Ifmore than one intermediate portion becomes necessary such could easilybe provided with each such intermediate portion having an increasinglygreater diameter as they lead from the first bore portion to the secondbore portion of the adaptor.

Turning now to FIG. 9 there is shown an embodiment which can be used tofill in a seal cavity if it is deemed necessary to do so, or if thecavity has a deep axial length and only a small first obstruction space.The first obstruction space is the physical space that is available forinstallation of the adaptor when the equipment is completely assembled.For example, the depth of the seal cavity might be 5 inches and thephysical space between the end of the seal cavity and the bearinghousing of the equipment might be only 3 inches. If the adaptor isprovided in two pieces, each being 2.5 inches long then one piece canfit easily within the cavity, in the available 3 inch space forinstallation. The second piece can then be installed, for a total lengthof 5 inches.

In this embodiment a spiral adaptor 28 as depicted in FIG. 2 isillustrated in conjunction with a cavity insert 130. The insert 130 hasan outer circumferential surface 132 sized for a sliding, tight fitwithin the cavity, the surface 132 being preferably, but notessentially, provided with at least two circumferential sealmember-receiving grooves 134. The inner bore 136 of the insert isprovided with a spiral groove 138 having a hand the same as thedirection of rotation of the shaft, which groove will merge smoothlywith the groove 56 found in the first annular portion of the adaptor 28.With this arrangement particulate material will be prevented frombuilding up within the seal cavity; as particulate material enters theseal cavity they are rejected by the spiral groove 138. The insert 130will be the first of the pieces mentioned above, the one that isinserted initially into the cavity while an adaptor 28 will be thesecond piece, the one that is inserted after the first piece to meet thecavity dimensional requirements.

FIG. 10 illustrates a spiral adaptor which is especially adapted for usewith an “agitator” type of rotary equipment. An agitator is a rotarycomponent that has a large blade assembly that rests inside a largertank, and rotates to “agitate” or mix the product within the tank. Thesetanks are common in the pulp and paper industry, the tanks beingtypically filled with a slurry of paper stock.

The rotary equipment used to effect agitation is prone to breakdown.Whenever there is a problem it is necessary to drain the tank beforerepairs can be effected to the mechanical seals. By utilizing theembodiment of FIG. 10 it is possible to avoid having to empty the tankbefore repairs can be effected. The spiral adaptor 140 of FIG. 10includes all of the standard features as described with respect to theother embodiments and, in addition, it is provided with a shutoffmechanism 142 which when activated will seal itself against the shaftwhen the shaft has been brought to a halt. The shutoff mechanism 142could entail a flexible sealant ring 144 held within a circumferentialgroove 145 in the bore 146 of the adaptor. A radially directed passageor bore 148 would be connected to a source of hydraulic or pneumaticpressure (not shown) which, when activated would force the ring 144 intosealing contact with the shaft. When such a shutoff mechanism isactivated with the tank full of product it would not be necessary todrain the tank in order to effect repairs to the mechanical seal.

In some applications the seal cavity might contain packing, with orwithout a separate mechanical seal, and it could be desirable tocontinue with such a configuration even when utilizing an externallymountable spiral adaptor of the present invention. FIGS. 11 and 12illustrate a situation in which packing can be used in conjunction witha spiral adaptor especially adapted for use therewith.

FIG. 11 shows a shaft 12, shaft housing 14 and a seal cavity 18, much asis shown in FIG. 1. The housing 14 includes a passage 150 for feedingflushing fluid to the seal cavity. An annular spiral adaptor 152 ispositioned deep within the cavity from the entrance of the cavity andone or more packing rings 154 are forced into an annular cavity 156defined between the adaptor 152 and the shaft 12, as will be seen fromFIG. 12, which shows the adaptor in greater detail. An annular glandplate 157 applies an axial force against the outermost packing ring tohold the rings in position. The gland plate 157 is secured to thehousing 14 by threaded bolts 158.

Turning now to FIG. 12, the adaptor 152 is described in greater detail.The annular body 160 of the adaptor 152 has a first annular portion 162having, preferably, an external circumferential groove 164 for receptionof a sealing ring (not shown). The annular portion 162 has a first bore166 and a spiral groove 168 therein as with the other embodiments. Asecond annular portion 170 has an outer circumferential groove 172 whichcommunicates with the passage 150 as well as one or more through bores174 communicating the groove 172 with the interior of the adaptor. Anoutwardly flaring, spiral grooved section 176 leads from the bore 166 toa radially inwardly tapering bore section 178, which in turn leads to ashort straight bore section 180, also provided with a spiral groove 182.

Outboard of the second annular portion 170 there is an annular extension182 which preferably has at least two circumferential grooves 184 in theouter circumferential surface thereof, each for reception of a sealingring (not shown). The extension 182 has an enlarged bore 186 whichextends inwardly thereof to an annular shoulder 188, against which theinnermost of the packing rings 154 will abut once the adaptor and thepacking have been assembled to the rotary equipment.

This embodiment is particularly advantageous where there is a largeradial cross-section being used, the adaptor being fittable externallyinto the seal cavity. This embodiment will permit the operator to reducethe diameter of the packing rings being used, while also permitting morepacking rings to be used than otherwise. For example, in large equipmentit would be possible to go from two rings of 0.750″ radial cross-sectionto three rings of 0.500″ radial cross-section. By being able to use morepacking rings, of smaller radial cross-section, it is possible to reducethe packing cost without sacrificing sealing efficiency.

FIGS. 13 and 14 illustrate a variation on the embodiment of FIGS. 11 and12. In this embodiment the extension 182 is provided with a radialflange 190 at the outboard end thereof, which flange helps to lengthenthe extension 182 and thus will allow for the inclusion of additionalpacking in the assembly.

With the new arrangement of externally mounting a spiral adaptor, andwith the adaptors illustrated herein, particulate or contaminantmaterial around the seal area will be removed or redirected away fromthe seal cavity. This arrangement will not remove particulate materialin the seal cavity having a throat restriction at the bottom thereof. Inan open or large bore box, this would not be a problem because there isno restriction in the bottom of the seal cavity. It is expected that askilled person in the art would be able to modify any of the spiraladaptors illustrated and described herein to accommodate a particularapplication without departing from the spirit of the present invention.Accordingly the protection to be afforded this invention is to bedetermined from the claims appended hereto.

1. A spiral adaptor for location at an entrance to an annular sealcavity of rotating equipment, such seal cavity being defined by a outercylindrical surface of a rotatable shaft of such equipment and a shafthousing surrounding at least a portion of said shaft, said cavity havinga bottom end, an entrance end and an outer cylindrical surface, saidequipment including a mechanical seal positioned outboard of said shafthousing adjacent said entrance to said seal cavity, said adaptorcomprising: an annular adaptor body having a central bore therethrough;said adaptor body including a first annular portion receivable withinsaid seal cavity at said entrance thereto and a second annular portionof greater diameter than said first annular portion, said second annularportion having an inboard radial surface adapted for contact with acomplementary face of said shaft housing and an outboard radial surfaceadapted for contact with a complementary face of said mechanical seal;said bore including a first portion defining an annular gap with saidshaft outer cylindrical surface when said adaptor is in its operatingposition and a second portion which flares outwardly from said firstbore portion towards said outboard radial surface, said first and secondbore portions each including a spiral groove formed therein, the handthereof being in the same direction as the rotation of said shaft, saidgroove serving to redirect contaminant material contained in fluidssurrounding said shaft away from said seal cavity.
 2. The spiral adaptorof claim 1 wherein said first annular portion of said adaptor body hasan outer cylindrical surface adapted for a tight fit within said sealcavity, said outer cylindrical surface including a circumferentialgroove therein for reception of an annular seal member adapted forsealing engagement with said outer cylindrical surface of said sealcavity.
 3. The spiral adaptor of claim 1 wherein said first annularportion of said adaptor body acts as a locating boss for positioningsaid spiral adaptor at said cavity entrance
 4. The spiral adaptor ofclaim 1 wherein said first annular portion of said adaptor body has anouter cylindrical surface adapted for a tight fit within said sealcavity, said outer cylindrical surface including at least a pair ofaxially spaced apart circumferential grooves therein, each for receptionof an annular seal member adapted for sealing engagement with said outercylindrical surface of said seal cavity.
 5. The spiral adaptor of claim1 wherein said inboard radial surface of said adaptor body secondannular portion has a ribbed gasket surface formed integrally therewithfor sealing engagement with said complementary face of said shafthousing.
 6. The spiral adaptor of claim 1 wherein said inboard radialsurface of said adaptor body second annular portion has an annulargroove formed therein for reception of an annular sealing member forsealing engagement with said complementary face of said shaft housing.7. The spiral adaptor of claim 1 wherein the axial extent of saidadaptor body first portion may be greater than, lesser than or equal tothe axial extent of said adaptor body second portion.
 8. The spiraladaptor of claim 1 including a shutoff mechanism contained therein, saidshutoff mechanism comprising a circumferential groove formed in saidfirst bore portion, a flexible sealing ring contained within saidcircumferential, and a passage in said annular body communicating asource of pressurized fluid with said circumferential groove forpressing said flexible ring against said shaft.
 9. The spiral adaptor ofclaim 1 in combination with an insert positionable within said sealcavity adjacent the bottom end thereof, said insert comprising anannular insert body receivable within said seal cavity and having acentral bore therethrough; said central bore including a first portiondefining an annular gap with said shaft outer cylindrical surface whensaid insert is in its operating position and a second portion whichflares outwardly from said first bore portion towards an outboard end ofsaid insert, said first and second bore portions each including a spiralgroove formed therein, the hand thereof being in the same direction asthe rotation of said shaft, said groove serving to redirect contaminantmaterial contained in fluids within said seal cavity towards said spiraladaptor.
 10. A spiral adaptor for location at an entrance to an annularseal cavity of rotating equipment, such seal cavity being defined by aouter cylindrical surface of a rotatable shaft of such equipment and ashaft housing surrounding at least a portion of said shaft, said cavityhaving a bottom end, an entrance end and an outer cylindrical surface,said equipment including a mechanical seal positioned outboard of saidshaft housing adjacent said entrance to said seal cavity, said adaptorcomprising: an annular adaptor body receivable within said seal cavityat said entrance thereto and having a central bore therethrough; saidadaptor body including an outboard radial surface adapted for contactwith a complementary face of said mechanical seal; said bore including afirst portion defining an annular gap with said shaft outer cylindricalsurface when said adaptor is in its operating position and a secondportion which flares outwardly from said first bore portion towards saidoutboard radial surface, said first and second bore portions eachincluding a spiral groove formed therein, the hand thereof being in thesame direction as the rotation of said shaft, said groove serving toredirect contaminant material contained in fluids surrounding said shaftaway from said seal cavity.
 11. The spiral adaptor of claim 10 whereinsaid adaptor body has an outer cylindrical surface adapted for a tightfit within said cavity, said outer cylindrical surface including atleast one circumferential groove therein for reception of an annularseal member adapted for sealing engagement with said outer cylindricalsurface of said seal cavity.
 12. The spiral adaptor of claim 1 whereinsaid spiral groove formed in said adaptor body bore first portion leadssmoothly into said spiral groove formed in said adaptor body bore secondportion.
 13. The spiral adaptor of claim 1 wherein said spiral groovehas radial and non-radial surface portions, the non-radial portionextending into the adaptor body from the adaptor body bore and theradial portion extending generally radially from the inner end of thenon-radial portion back towards the adaptor body bore.
 14. The spiraladaptor of claim 1 wherein said adaptor body bore includes anintermediate portion between said first and second portions and ofdiameter greater than that of said first portion, there being a flaredtransition section between said first and intermediate portions, saidintermediate and flared transition portions each having a spiral grooveformed therein.
 15. A spiral adaptor for location within an annular sealcavity of rotating equipment, such seal cavity being defined by a outercylindrical surface of a rotatable shaft of such equipment and a shafthousing surrounding at least a portion of said shaft, said cavity havinga bottom end, an entrance end and an outer cylindrical surface, saidadaptor comprising: an annular adaptor body receivable within said sealcavity and having a central bore therethrough; said adaptor bodyincluding a first annular body portion positionable at said bottom endof said seal cavity and a second annular body portion outboard of saidfirst body portion; said bore including a first portion defining anannular gap with said shaft outer cylindrical surface when said adaptoris in its operating position and a second portion which flares outwardlyfrom said first bore portion towards a radially inwardly taperingcentral portion, said first, second and central bore portions eachincluding a spiral groove formed therein, the hand thereof being in thesame direction as the rotation of said shaft, said groove serving toredirect contaminant material contained in fluids surrounding said shaftaway from said seal cavity; and said adaptor also including an annularextension portion extending from said second annular portion to anoutboard end of said adaptor, said extension portion including a blindbore therein which, with said shaft outer cylindrical surface defines anannular cavity for reception of one or more packing rings.
 16. Thespiral adaptor of claim 15 wherein said second annular portion includesan outer circumferential groove therein for communication with a sourceof flushing fluid, and at least one passage leading from saidcircumferential groove through said adaptor body to said bore centralportion.
 17. The spiral adaptor of claim 15 wherein each of said firstannular portion and said extension portion includes at least one outercircumferential groove therein for reception of an annular sealingmember.
 18. The spiral adaptor of claim 15 wherein said extensionportion terminates at its outboard end at a radially outwardly extendingflange.
 19. The spiral adaptor of claim 10 wherein said spiral groovehas radial and non-radial surface portions, the non-radial portionextending into the adaptor body from the adaptor body bore and theradial portion extending generally radially from the inner end of thenon-radial portion back towards the adaptor body bore.
 20. The spiraladaptor of claim 10 wherein said adaptor body bore includes anintermediate portion between said first and second portions and ofdiameter greater than that of said first portion, there being a flaredtransition section between said first and intermediate portions, saidintermediate and flared transition portions each having a spiral grooveformed therein.